Frequencies for first 10,000 rows of drugtst3 variable in person dataset :

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,941       99.41       99.41
          1 |         25        0.25       99.66
          2 |          6        0.06       99.72
          3 |         14        0.14       99.86
          7 |          1        0.01       99.87
          8 |         12        0.12       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016